Many types of bone fixation systems are conventionally available to stabilize bone fragments following bone fractures to promote bone healing. Bone fixation systems typically include a bone plate that is placed against the bone across the fracture location. Bone anchors, typically configured as bone screws, are driven through bone fixation holes of the bone plate and into the respective underlying bone fragments. The bone fragments are thus stabilized with respect to the bone plate and each other. The bone fragments can be compressed toward each other prior to reduce the fracture prior to fixation of the bone anchors.
Bone screws are conventionally available as locking screws or non-locking screws (also known as compression screws). Locking screws are configured to lock to the bone plate. For instance, locking screws typically can be externally threaded at the screw head, and the bone plate typically includes threading in the fixation hole. The locking screw is inserted through the fixation hole of the bone plate, and rotated to gain purchase with the underlying bone as it is driven into the bone. The locking screw is rotated until the screw head is inserted into the fixation hole, at which point the threading of the screw head purchases with the threading in the fixation hole. Thus, the locking screw is locked to the bone plate, thereby creating a fixed angle construct and preventing back out of the bone screw.
Alternatively, the bone screws can be configured to compress the bone plate against the underlying bone. In particular, the external surface of the bone screw can be unthreaded. Accordingly, the bone screw is driven into the underlying bone until the screw head bears against the bone plate (typically in the fixation hole). Continued rotation of the bone screw causes the screw head to compress the bone plate against the underlying bone. This can be useful when it is desired to compress two or more bone fragments against each other to promote bone healing. Unfortunately, conventional locking screws are not also configured to cause compression of the bone plate against the underlying bone.
Unfortunately, many high-energy fractures produce highly comminuted fractures that are not easily addressed with conventional bone plating techniques. Intra-articular and juxta-articular fractures typically result in highly comminuted fractures. In particular, the small bone fragments associated with highly comminuted fractures are too small to receive bone screws. As a result, these bone fragments are often left untreated.
It is therefore desirable to provide a bone plate that is configured to stabilize highly comminuted bone fractures.